Slack adjuster for railway car foundation brakes



April 2Uf1954 c. M. O'BOYLE SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES Filed NOV. 15, 1949 9 Sheets-Sheet l g 0 0 O Q \Q 1% %Q, m Q\\.\ QM. O

Charles M. 0' Boyle BY mwm mwmu ATTORNEYS April 20, 1954 c. M. O'BOYLE 2,675,894

SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES Filed Nov. 15, 1949 9 Sheets-Sheet 2 m v *3 no g '0 I} v INVENTOR. Charles M. O'Bpyle BY wwww wwamv ATTORNEYS April 20, 1954 c, O'BQYLE 2,675,894

SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES 9 sheets sheet 3 Filed NOV. 15, 1949 INVENTOR. Charles M. OBoyle Wilma Ma-Mu,

ATTORNEYS c. M. O'BVOYLE A ril 20, 1954 SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES 9 Sheets-Sheet 4 Filed Nov. 15, 1949 INVENTOR.

Charles M. O'Boyle ATTORNEYS April 20, 1954 c.- M. "O'BOYLE 2,675,894

SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES Filed Nov. 15, 1949 9 Sheets-Sheet 5 m m u 2, m mm m I mnfi II... I" 1 1 M m 1 m I in M 4 m G l v6 m 0-.

ATTORNEYS April 20, 1954 c. M. "O'BOYLE ,894

' SLACK'ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES Filed Nov. 15, 1949 v 9 Sheets-Sheet 6 /III/IIIIIIJ 4 INVENTOR; BY Charles M. OBoyle Mum ww w AT'IORNEYS April 1954 c. M. "Q'BOYLE SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES Filed Nov. 15, 1949 9 Sheets-Sheet '7 I NVENTOR. Charles M. O Boyle.

ATTO R NEYS April 20, 1954 c. M. 'O'BOYLE 2,675,894

SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES 9 Sheets-Sheet s Filed NOV. 15, 1949 A Bud-L 3 A15 84 8 2. E WW-m 4 an -t/J/N/ llnlallclullulllll. n

6N 2. am

' zzvmvrox. Charles M. OBoyle WNW. ATTORNEYS April 1954 c. M. O'BOYLE 2,675,894

SLACK ADJUSTER FOR RAILWAY CAR FOUNDATION BRAKES Filed Nov. 15, 1949 9 Sheets-Sheet 9 FIG.29.

Charles M. O'Boyle 50g go-' so IN VENTOR ATTORNEYS Patented Apr. 2O, 1954 UNITED STATES PATENT" OFFICE SLACK ADJUSTER FOR RAILWAY-CAR A FOUNDATION BRAKES Charles M. OBoyle, Wilmington, Del. Application November 15, 1949, Serial No. 127,342

19 Claims. (01. 188-200) l The present invention relates to improvements in slack adjuster for railway car foundation brakes and more particularly consists in certain improvements over such prior patents as 1,612,781

the form and construction of prior devices intended to accomplish this same purpose by simplification .in both structure and mode of operation, and in promoting greater achievements in reliability and efliciency inoperation...

A further object of the inventionis to provide an improved slack adjuster adapted to automatically align with the connection to the brake. rigging orrto the upper end of the dead lever to the end that the slidable and rotatable rack bar of the improved adjuster will not bind in the saddle bearing and will at all timesbe comparae tively easy to operate. 7

With the foregoing and other objects in view, the invention will be more fully described here? inafter, and will be more particularly pointed out in the claims appended hereto.

In the drawings, wherein the symbols refer .to

like or corresponding parts throughout the several views,

Figure 1 is a fragmentary side elevationalview; with parts broken away and parts shown in sec tion of a truck of a railway freight car showing a portion ,of the brakerigging including the dead lever to which is connected by a clevisor the like a novel form of slack adjuster constructed in accordance with the present invention.

Figure 2 is a top plan view of one form of slack adjuster in accordance with thepresent invention with parts broken away and parts shown in section.

Figure 3 is a longitudinal sectional view taken I on the line 3-3 in Figure 2 and showing the rack bar in an inner position. V Figure .4 is a similar viewwith portions oirthe rack bar broken away and shown. in an outer"- position free of the pawl.

Figure 5 is a transverse sectional .view' taken on the line 5- -5 in Figure 3.

Figure 6 is a longitudinal sectional view taken on the line 6-6 of Figure 9 and showing a modified form. of slack adjuster with the rack bar locked against further inner movement by the pawl. V

Figure 7 is across-sectional view taken on the line l--! of Figure 6.

Figure 8 is a view similar to Figure 6 with a portion of the rack bar broken away and shown as rotated about. its longitudinal axis to remove its teeth from engagement with the teeth of the pawl. v

Figure 9 is a top plan view of. the slack adjuster according to. Figures 6, 7 and 8 with the end of the rack bar broken away.

Figure 10 is a diagrammatic plan view showing in broken lines, a railway freight car and its trucks with a form of foundation brake rigging shown connected with acentral or side operated form of slack adjuster according to the present invention.

Figure 11 is a side elevational view of the same. v

Figure 12 is a longitudinal sectional view taken throughthe central form of slack adjuster with the. rack. bar locked against, further outward movement..- l V p V Figure .13 is a similar view with the pawl disengaged from the rackbar and the rack bar movablev outwardly. V.

Figure 14 is a cross-section taken on the line "-44 of Figure 12.

Figure 15 is a similar view taken on the line l5--l5 in Figure 12. Y

Figures 16, 1'7 and 18 are fragmentary vertical sectional views showing subsequent .phase movements the operation-of this form of the in? vention.

Figure'19 isa perspective view of a still fur-- 'ther modified form of the device with a completely enclosed trunnion support for the pawl instead of the pin support- Figure 20 sf a longitudinal section taken through the. housing of'Figure 19 with the rack bar in the inwardly pushed position.

Figure 21 is a bottomplan view of Figure 20.

Figure 22 isa'longitudinal Section taken on the line.22-22' of Figure21 with the rack bar and pawl removed butshowing in section one of the pawl trunnions in the pocketed bearing.

Figure' 23 is'across-sction taken on theline Figure '24 is a: longitudinal section taken: fthrough a modified form of the center slack ad;

juster showing an arrangement of enclosed trun- Figure 30 is a horizontal section taken on the line 3il-3ll in Figure 29.

Referring more particularly to Figure 1, 25 represents a longitudinal sill or other frame portion of a railway freight or other car truck and 26 indicates a transverse truck bolster of; any ordinary four-wheel freight. car truck, for example, to one side of which is positioned a dead. lever 21 which in: practice normally occupies a diagonal position of substantially 45 with respect, to thethreeintersecting right angle planes. This dead lever is connected at its lower end to one end of a push or bottom rod 28, the offset. end of which: rod is pivotally connected to the lower end of a live truck lever 65; These levers are, of. course, provided with brake beams and. support-- ing connections 66 adapted to carry the usual brake shoe heads and shoes (not. shown). for engagement with the wheels 61. The upper end of the live lever 65 is provided with a pull rod 631' connected to the outer endof a horizontally dis.- posed cylinder lever 89 which moves. back and forth on a supporting stop. Ill.

This supporting stop may be of the common U-shaped; typeofhanger depending from the: underside of the car or draft sill although the. stop locations may beprovided by an elongated slot in the draft sills or by any other form of, stop arrangement common in this. art. The essential feature of this supporting stop regardless of the form it may take, is either. in. its;

accurate positioning or the provision of means...

therewith for limiting the relative.- movement, of

the cylinder lever 69- asshown toward the, left;v

are old and well-known and need no.f.urther dc:-

tailed description.

The upper'enclof.v the, dead lever; 21; is anchored.

against, relative movement towards the right during the application movement of the brake by means, of a. regulator attached: to the car sill 25. One. form of this regulator or slack adjuster. is.

shown. more particularly in Figures, 2 to 5 inclusive.

A. clevis 29 is shown as coupling the upper end of the dead lever 21" to the inner end of a rack bar 30 of the improved slack adjuster.

The rack bar is'fitted' toslide through ahousing 31 affixed to the longitudinal sill or frame 25 in anysuitable manner. In this instance a flange 32 of thehousing is bolted; to the-sill 25; The. housing is closed. at. its upper enclas. shown in. Figure 5' and is. open at oppositeends; as; shown; in- Figure 3, forms freeslidingimovementof the rack bar 30 therethrough. A. handle. 3.3;.011 the, outer end. of the rack: bar facilitates this sliding movement. V

As shown in Figure 5 the parallel spaced side plates 34 and 35 of the housing are open at their lower central portions, the plates being formed with centrally and downwardly offset portions 36 to constitute bearings for a pin 3'! by means of which a pawl 38 is rotatably mounted in such position that its teeth are adapted to mesh with the teeth 39 in the lower edge of the rack bar 313.

End bars 40. and 4| extend across the lower opposite end portions of the side plates 34, 35 and preferably have their upper surfaces rounded in a longitudinal direction so that the rack bar 30 and its teeth 39 may freely slide over these surfaces and receive support from them when the pawl is withdrawn from the rack bar teeth 39. The rounded surfaces of the end bars 4t and M will avoid any sharp corners or the jamming of the rack bar in the housing.

The pawl has an offset part 42 which eccentrically weights the pawl so as to set up therein a condition of stable equilibriumin which this weighted offset part 12 will seek by gravity the lowermost position in the rotationv of the pawl about the pin 3].

Thepawl has an initial pawl tooth 3.3 which is concentric with the pawl center as are also the companion pawl teeth 44. The offset portion =22 also has one or more tangential teeth it. These teeth 43, M, and it are spaced apart in a manner 1. complementary to. the teeth 39 of the rack bar teeth.

A pawl pin 46 projects from a corner portion of the offset part 42- remote from the teeth 45. Otherwise stated this pawl pin :36 projects laterally from the leading edge of the pawl offset part i-2-rin reference to the counter-clockwise rotation of the pawl from the position shown in Figure 3 to that shown in Figure 4.

In: the operation of' this. form of the invention, in order to adjust piston travel, the handle 33 is pulled in the direction of the arrow shown in Figure 3 toward the end of the car as far as possible and subsequently the handle 33 is pushed back towards the center of the car until its motion is arrested.

Now when the handle is pulled to the left from the position of Figure 3 the rackteeth 39 meshing with the pawl teeth cause the pawl to execute ananti-clockwise movement with the lateral pawl pin 46 moving about beneath the curved dropped intermediate wall 35 of the outer side plate 35. This rotary motion of the pawl will continue until only the initial tooth Z3 isin engagement with the rack bar teeth 39 at which angular position of the pawl the oifset weighted part 42- Will be to the right side of the center of the pawl rotation so that this weight, tending by gravity to descend back in the clockwise direction will" maintain the initial pawl tooth 43 in engagement with the rack bar teeth 39. As the rack bar 30- ispulled out to the left, this initial pawl tooth 43 will ride over the teeth 39 of the-rack bar 3i] and by virtue of the weighted offset &2 will immediately re-engage the next presented notch between the 'rack bar teeth 39, so that after the rack bar 30 has been pulled out to the extreme limit permissible by the brake rigging after all the slack has been. taken upzand is then pushed back, the initial pawl 43 in. concert with the weighted offset part 42 having kept all the while the tooth engagementbetween rack bar and pawl tooth, such return movement of the rack bar acme will necessarily be attended .bythe clockwisejro= tation of the pawl 38 establishing progressively re-engagement of the concentric pawlteeth 44 with the rackbar and finally the re-engagement of the offset tangential teeth 45. .When the position of Figure 3 isarrived at the tangential offset 42 will assert its second function of a stop. In other wordsewhen this position of Figure 3 is reached the pawl 38 can rotate no longer in a clockwise direction under the urge of the inward movement of the rackbar 30 unless the rack. bar 30 ,couldrise to permit thepassage of the offset pawl part 42 therebeneath, but theclosed upper end of the housing 3| prevents this". lifting of the rack bar 30. Consequently the rack barcan only be pushed in a distance controlled by the;offset stop 42.

, ,Inordergto change brake shoes, the handle 33 is, pulled in the direction of the. arrow shown in Figure 3 towards the end of the car as far aspossible. The pin 46 is then grasped in the hand of the, Operator and pushed upwards until it strikes the lower edgeof the front plate35 of thehousing which will act as a stop. In this position, as shown in Figure 4, theinitial pawl tooth 43 is completely disengaged from the rack bar teeth 38. Thereupon the rack bar 30 without interference from the pawl 38 is pushed toward the center of the car as far as possible. This introduces the maximum slack in the brake rigging so that the brake shoes may be moved to a sufficient distance from the wheels toenable the old worn shoes to be removed and new brake shoes applied. 7

After the application of the new shoes the pin 46 is released and the rack bar 33 pulled outwardly in the direction of the arrow in Figure 3 toward the end of the car as far as possible, the initial pawl 43 simply clicking over the rack bar teeth 29. Thereafter the, rack bar 30 is pushed back toward the center of the car until the stop offset 42 arrives the position of Figure 3 and arrests further. inward movement of the rack bar 30. The new shoes arethereupon brought to correct clearance position with respect to the wheels in a proper relationship to lthe piston travel of the brake cylinder piston.

It will be understood that onevormore teeth 45 may be provided on the tangential projection of the pawl '38. a

Referring more particularly to Figures 6 to 8 inclusive, the rack bar 311 is round in cross-sec tion so as to be both longitudinally slidable and rotatable in the lower closed portion of a substantially. U-shaped saddle 41.

The saddle 4! is pivoted on the pin 31 which erably downturned vertically when the teeth 39 7 of the rack bar are vertically'upwardfin position,

riveted or otherwise affixedto a flange of the center or other-sill of a railway freight car.

A stop 48 in the housing is adapted toencounter the heel 49 of the pawl offset part 42*. I In the use of the device, to adjust piston travel, thehandle 33 is pulled toward the leftin Figure 6 tionuntila desired amount of slackistaken up in the foundation brake rig ing. It is understood that the brake rigging in general use on freight cars is so arranged that all movement to the brake levers is operated by asingle brake cylinder and provision must be made to effect brake adjust ments at each end of the car so that the brake rigging can be adjusted to avoid developing acute angles of thelevers. Stops 10 are ordinarily pro-g vided to maintain the correct angles of the brake levers, which stops limit the movement of the brake levers towards release position. When operating the brake adjuster, the operator pulls the operating handle 33 out or to the left in Figure 6 until the brake shoes are tight against the wheels and one body brake lever is pulled against its stop position. See Figure l. The stop location prevents the body brake levers and live truck levers from being pulled to an acute angle and has the effect of maintaining a proper .balance on the foundation brake rigging. The stop is the end portion of the lever guide. The lever guide is located so that one end forms a stop position for the movement of the lever.

During this operation the tangential section 42 of the pawl moves out of contact with the rack bar 30 and the arcuate teeth 44 maintain con tact with the teeth of the rack bar a predetermined distance before permitting the rack bar to move freely towards the operator to take up the slack in the brake rigging. In other words when the rack bar 30 is shifted to the left in Figure 6 it causes clockwise rotation of the pawl 38 until the offset portion 42 has arrived at the upper portion of the circle and with the initial tooth t3 alone in mesh with the rack bar teeth 39; but the center of mass or the center of gravity of the offset part 4i does not pass the vertical dead center so that the initial tooth 43 is maintained in the teeth 39 of the rack bar. In other words as the rack bar moves to the left this initial tooth 43 slides up and down on the walls of the rack bar teeth 39 permitting of the movement of the rack bar 3i] to the left but still maintaining withthe entrainment of the teeth of rack bar and-pawl so that on reverse movement of the rack bar the pawl will be rotated back down to the position shownin Figure 6 where the offset part 42 forms a, lock stop preventing the further inward movement of the rack bar 30 After the handle 33 has been pulled out to the desired distance it is simply released whereupon the weight of the brake rigging causes the rack bar 30 to move in the opposite direction and the.

pawl 38 being counter-weighted by the offset part 42% again engages the rack bar and permits movement of the rack bar a specified distance before locking the rack bar and pawl'against movement by the engagement of the tangential teeth 45.

with the rack bar teeth.

When necessary to release the adjuster to pro vide for additional slackin the foundation brake,- for instance in applying new brake shoes,;.the. rack bar 30*- is pulled out'by the operating handle 33*- a sufficient distance to throw the arcuate teeth44 out of engagement with the rack bar; at. which time the rack bar is given a rotary or angular movement, for instance one-eighth of a turn,- to rotate the rack bar teeth 39 out of engagement with the teeth of the pawl so that the rack bar: can be moved inwards from the operator to its-- full initial position. This action is shown in Figure 8 in which'the initial tooth 45% of the pawl is riding upon the roundedblar k surface of the rack:

aus he i t-tab? weighin ime-.5 7 team enser In this position the heel 49 or the pawl engages the housing stop 48 to prevent the overthrow of the ofiset part ll beyond the upper dead center position which would throw it out of proper relationship with the rack bar. When the rack bar is pushed all the way in as shown in Figure 8 the maximum slack is permitted in the rigging to pull the brake shoes to a maximum distance away from the wheels whereby new brake shoes may be easily substituted.

After the substitution the slack is adjusted in the usual manner by pulling out on the rack bar and subsequently releasing the rack bar so that it may be pulled back by the weight of the'brake rigging a distance permitted by the stop offset part 42 The swiveling of the saddle 41 around the pin 31 in the housing permits a vertical movement of the inner end of the rack bar to maintain proper alignment of the rack bar with the'tops of truck levers of varying heights above the top of the rail to maintain the alignment due to spring deflection of the trucks or other causes.

Referring more particularly to Figures 10 to 18 inclusive, a device is shown adaptedto be coupled into the brake rigging at a central position and for operation centrally at one side of the car. In this case a housing 3 l is coupled to one member 50 of the central connecting rod of the brake rigging and a rack bar SB is coupled to the second member 5| of the brake rigging central rod. In other words the slack adjuster is included in the central connecting brake rigging rod 55, 51. The rack bar 35 slides freely within the housing 31* and has its teeth 39* disposed in mesh with the teeth of a pawl 38 This pawl is mounted to rotate about a pawl shaft or pin 37* journaled cross-wise in the housing. The pawl has an initial pawl tooth 43 radial teeth N and tangential teeth 45 in an offset portion 42*. In addition the end wall of the offset part 52 is provided with additional teeth 52. As shown in Figure 1a the axial width of the pav'vltii may be as great as the Width of the rack bar 30*.

' Apinion 53 is shown as disposed in mesh with the teeth 39 of the rack bar 35 such pinion being fixedly mounted on a pinion shaft '54 journaled laterally through the housing 3| b and having a handle 55 on its outer end accessible for rotation at the central side portion of'the freight car as indicated in Figures and 11..

Arranged coaxially of the pinion and within the shaft is a trip member 56 fixed upon a sleeve 51 which rotates about the pinion shaft 54 and has an independent handle 58 accessible for rotation at the central side portion of the freight car as angular or rotary movement of the trip member 55 in both directions. At one peripheral portion namely that disposed toward the pawl 38 the trip member 56 is formed with teeth 62.

In Figure the pinion 53 is shown as being narrower in width than the width of the rack bar 39 in order to provide lateral space beside the pinion '53 for the accommodation of the trip member in the same plane as the pawlilli to permit meshing of the end wall pawl teeth 52 and the teeth 52 of the trip member 56.

In theoperation of this form of the device,Figme 12 shows the regulator in the'locked (applied) position in which the rack bar 30 and the housing 3| cannot be further separated due'to the fact that the offset part 42' of the pawl is in engagement with the lower side of the rack bar. In this position the shoulder 60 of the trip member 56 is against or substantially against the stop 6| so that the teeth 52 and the teeth cavities of the trip member 56 are disposed in a lowermost position adapted to receive the complemental end wall teeth 52 of the pawl 38 when the same shall have been rotated clockwise to a position to mesh with the same.

Figure 16 shows the rack bar 30 having been moved in the direction of the arrow with respect to the housing Bi causing a partial rotation of the pawl 38 in a clockwise direction. The rack bar 30 is started and moved toward a release position by turning the handle 55 on the pinion shaft 54 in a right hand direction. I

Figure 17 shows that the handle 55 has been rotated to a further position and that the rack bar 30 has advanced to a further degree within the housing 3 l b so that the pawl 38 has now been rotated to a point where its offset 42 has passed the vertical line and is now exerting its weight to maintain the initial tooth 43 of the pawl in the teeth of the rack bar 30*. The pawl teeth 52 are approaching the trip teeth 52.

In Figure 18 the rack bar has moved further inwardly toward release position by the continued turning of the pinion shaft handle 55. The pawl end teeth 52 are now in mesh with the trip teeth 2 and the trip has started to move in a counterclockwise direction so that its shoulder 55 has moved away from the stop iii.

In Figure 13 the rack bar has moved further towards release position by the further turning of the pinion 53, pinion shaft 54 and handle 55. At this point the rack bar 30 has ceased to move the pawl 38 The trip handle 58 is now moved counter-clockwise to rotate the trip member 56 in the direction of the arrow indicated in Figure 13. This movement further shifts "the pawl 38 and disengages its initial tooth 43 entirely from the rack bar, thus permitting movement of the rack bar 30 in either direction by rotation of the pinion handle 55.

The movement of the trip handle 58 may be continued'until shoulder 55 of the trip member 56 engages the stop 61. Thereupon the trip handle 58 is reversed in direction, causing the trip member 56 to return in a clockwise direction to the position of Figure 17 until arrested by its shoulder 60 encountering the stop 6!. Such movement of the trip member causes the pawl 38 to reversely rotate in a counter-clockwise direction and reengage the initial tooth 43 with the rack bar 30*. The pawl 38 may now be rotated back to locked position (Figure 12) by turning the pinion shaft handle '55 in a direction to move the rack bar 30' outwardly of the housing 3| In Figure 18 the initial pawl tooth 43 is shown entering a cut in rack'bar 30 to makea one-tooth take up. One ormore teeth can be taken up by rotating pinion shaft handle 55 first toward release position as far as ,possible and then back to the locked position of Figure 12. The trip handle "58 does not have to be used to take up the slack in the brake rigging. It is used only to let out the regulator when brake shoes are changed.

A stop pin 63 may be mounted through the top wall of the housing 31 and entered into a groove 64 in the upper end of the rack bar 30 to entrain the rack bar and housing against casual or accidental separation. This stop pin 53 is weighted offset part 42.

"64"whenever it is desired to disassemble the parts. 1 Referring more particularly to Figures 19 to 23 inclusive, the rack bar 30 is slidable in the housing 3l which is attached by flange 32 to a sill or other part of the framework of the car. The

handle 33 is detachableffrom the rack bar 300 as by screw threading. j

The housing 3 l has sideplates 34 and 35 with central downwardly-offset portion 36 formed to accommodate the trunnions 31 of the pawl 38. The teeth 39 of the rackbar mayride on the upper curved surfaces of the end bars 40 and 41 which connect the lower edges of the side walls of the pawl.

.The side walls 34, and 35 are completely and have noopenings therein but they are offset outwardly to provide pocketed bearings 11 which are at the ends of volute channels 12 having the open channel mouths 13. Vertical walls 14 separate the, bearings 1| from the mouths 13.

Curved bottom walls 15' form continuations of the vertical wall and provide the bottoms of the bearings H. i v

' It will be noted that in this form of the device the trunnions 31 replace the pins of the other .forms, which pins projected through openings in the sidewalls of the housing] In assembling the device, with the rack bar 30 removed from'the housing 31, the two trunions 31 which project in opposite directions from. the pawl z38 are intro- .duced-upwardly-into the channel mouths 13 and moved through the volute channels v12 until the trunnions 31 arrive over the pocketed bearings 1|, from which point such trunnions will descend bygravity into the-pocketed bearings 1| and be retained therein by the vertical walls 14. When the rack bar 30 is subsequently introduced into the-housing 3| itwill form an obstacle for pre venting the pawl 38 lifting to an-extentwhich would permit the trunnions 31-to escape. upwardly over the verticalwalls-14.

This formof the device provides a completely closed housing for preventing foreign deleterious substances from getting intothe bearings and trunnions andlfreezing the device into inoperathe end openings through which the rackb'ar slides; The purpose also is to avoid anypins or shafts projecting to' the exterior walls of the housingor casing which might expose'crevices-or slots in which corrosive chemicals or other deleterious substances'might find theirway into thetrunnions' and bearings and other internal parts, rusting, eating or otherwise so attacking the same that the parts'will become immobile "from freezingorfrom the concentrated harden- 10 in g accumulations of these chemicals or other substances. 1 I

The opening in the bottom parts of the housing not only permits the introduction and removal of the trunnions and the pawl but also forms an exit or evacuation opening whereby any foreign material that might accidentally find its way into the casing, for instance through the end openings, would fall by gravity and thus be automatically evacuated. V

It is to be noted that thehOusing is open for the major portion of its length all the wayalong its bottom wall which permits any accumulations of foreign matter to drop through; it being understood that these accumulations tend to become dislodged by the reciprocation of the rack bar which has the effect to also draw these ac:- cumulations clear of the pawl so that the same "may drop through the open bottom of the device.

In addition to the open bottom, the mouths of the trunnion slots or bearingopenings provide for the evacuation of any accumulations of foreifgn material in the'bearingportions of this device. The natural vertical oscillation and ,vibration of the car while in motion will provide'a means for eliminating any foreign substances that might tend to accumulate within the housing.,

The trip or release 'pm 46 is applied tojbo th sides of the pawl in all cases whether the trunnions are cast on the pawls or a pin is used instead of the trunnions. The reason for the double trip or release pin 46 is that thesame increases the counter-weight effect of the trip pin and also provides an additional pin in the event of one being broken.

Referring more particularly to Figures 24" to 28 inclusive, the trunnion principle is shown as applied to the center type regulator in which 30 indicates the rack barwhich is attached to one member 5|! of the brake rigging extending to one truck, and 314 represents the housing in which the rack bar slides and which housing is attached to the other member 50 of the brake rigging extended to the other end of the car,

In this instance-the pawl 38 is provided with trunnions 31 and the side walls 34 and35 of the housing 3l are blank walls except as later I I Suchside walls 34 and 35 are offset outward- 1y, as indicated in Figure 27, to provide pocketed bearingsfll' f (Fig, 26) for the trunnions 31 of the pawl 38 Such trunnions are moved into the bearings through volute channels 12, the

' trunnions being introducible through mouths 13 of the channels" which open downwardly through the bottom portion of the device. Vertical'walls 14 divide the bearings 1| from" the mouths'13 and'form a pocketed bearing arrangement for'holding the trunnions 31 in place with the aid of the rack bar 30 which prevents the pawl 38' from rising to any considerable extent. The bottom walls 15 form supports for the bearingsfand close the lower sides of the pocketed ear ng 1| The pinion 53 is'fixed to-the pinion shaft 54 whichextendsoutwardly-transversely of the car and to the side; thereof atthe central portion of the'car where such shaft is provided with a han dle 559 Similarly the trip member 56 is carried by a sleeve '51 which freely rotates about the shaft 54 and is operable by a handle '58 adjacent the handle' 55 The pinion 53 ispr'ovided with a hollow trunni'on 8'! at the-side opposite the sleeve 51 and thistrunnion is adapted to be rotatably mounted in a pocketed bearing H in an ofiset portion of the housing side wall 3. The pocketed bearing is accessible through avolute channel 11 having a mouth 78 at the lower portion of the housing. A vertical wall 19 separates the bearing 16 from the mouth 18. An opening 80 in this side wall 34 is made for purposes of assembly of the sleeve, shaft and other parts. The other side wall 35 has a bearing 82 for the sleeve 51.

The operation of this form of device is the same as that described in connection with Figures 12 to 18 inclusive.

Referring more particularly to Figures 29 and 30 an application is shown of the center regulator to floating lever of box car brake in which the floating lever is designated at 69 and its lever guide at this lever being coupled by the rods 50 and 51 to the brake rigging at opposite ends of the car. One end of this lever 69 is pivoted to the rack bar 30 of the improved center regulator, which rack bar slides in the housing 31- attached to the under frame of the car at its central portion. At 5'! is indicated the trip sleeve and pinion shaft assembly.

Although I have disclosed herein the best form of the invention known to me at this time, I reserve the right to all such modifications and changes as may come within the scope of the following claims.

What I claim is: V

l. A slack adjuster for railway car foundation brakes comprising a movable rack bar having slack take-up and slack-restoring strokes and adapted to be connected to the brake rigging, a rotary pawl having a segment of radial teeth meshing with the rack bar teeth for driving the pawl from the rack bar. in relatively opposite directions incident to the stroke movements of the rack bar, said rotary pawl having a blank toothless segment brought opposite the rack bar when the pawl is rotated in slack take-up direction to permit the rack bar to move relatively to the pawl in the act of taking up slack in the rigging, and a stop weight on the pawl positioned to encounter the rack bar as a stop to arrest the rotary movement of the pawl and consequently the degree of slack-restoring movement of the rack bar incident to the entrainment of the rack bar with the radial teeth of the stopped pawl i and to be moved on the slack take-up stroke of the rack bar to an angular position where its weight mass will bias the initial tooth of the pawl adjacent the blank portion to constant entrainment with the rack bar to permit the rack bar to advance relatively to the pawl on a slack take-up stroke but to prevent loss of entrainment of the pawl with the rack bar.

2. A slack adjuster for; railway car foundation brakes comprising a movable rack bar having slack take-up and slack-restoring strokes adapted to be connected to the brake rigging, a' rotary pawl having a segment of radial teeth meshing with the rack bar for driving the pawl from the rack bar in relatively opposite directions incident to the stroke movements of the rack bar, the teeth of said segment all being struck on the same circle to which the rack bar teeth are tangent, said rotary pawl having a blank toothless segment brought opposite the rack bar when the pawl is rotated in slack take-up direction to permit the rack bar to move relatively to the pawl in the act of taking up slack in the rigging, and a stop weight on the pawl positioned to encounter the rack bar as a stop to arrest the 1'0- tary movement of the pawl and consequently the degree of slack-restoring movement of the rack bar incident to the entrainment of the rack bar with the radial teeth of the stopped pawl and to be moved on the slack take-up stroke of the rack bar to an angular position where its weight mass biases the initial tooth of the pawl segment-to constant entrainment with the rack bar to permit the rack bar to advance relatively to the pawl on a slack take-up stroke but to prevent loss of entrainment of the pawl teeth with the rack bar.

3. A slack adjuster for railway car foundation brakes comprising a movabl rack bar having slack take-up and slack-restoring strokes and adapted to be connected to the brake rigging, a rotary pawl having a sement of radial teeth meshing with the rack bar teeth for driving the pawl from the rack bar in relatively opposite rotary directions incident to the stroke movements of the rack bar, said rotary pawl having a blank toothless segment positioned to be brought opposite the rack bar when the pawl is rotated in slack take-up direction to permit the rack bar to move relatively to the pawl in the act of taking up slackin the rigging and for the purpose of freeing the rack bar from the pawl to allow th rack bar to move all the way on a slackrestoring movement to an origin position, and a stop weight on the pawl positioned to encounter the rack bar as a stop to arrest the rotary movement of the pawl and consequently the degree of slack-restoring movement of the rack bar incident to the entrainment of th rack bar with the radial teeth of the stopped pawl and to be moved on the slack take-up stroke or the rack bar to an angular position where its weight mass biases the initial. tooth of the pawl adjacent the blank portion to constant entrainment with the rack bar to permit the rack bar to advance relatively to the pawl on a slack take-up stroke but to prevent loss of entrainment of the pawl teeth with the rack bar.

4. A slack adjuster for railway car foundation brakes comprising a movable rack bar having slack take-up and slack-restoring strokes and having means to connect the same to the brake rigging, a rotary pawl having a plurality of continuous radial teeth all struck on the same circle to which the rack bar is tangent and meshing with the rack bar teeth for driving the pawl from the rack bar in relatively opposite directions incident to the stroke movements of the rack bar, said rotary pawl having a blank toothless portion adjacent the radial teeth angularly positioned to be brought opposite th rack bar when the pawl is rotated in full slack take-up direction to permit the rack bar to move relatively to the pawl teeth in the act of taking up slack in the rigging and for the purpose of freeing the rack bar from the pawl teeth to permit the rack bar to move all the way on a slack-restoring stroke to an origin position, a stop weight on th pawl angularly positioned to encounter the rack bar as a stop to arrest the rotary movement of the pawl and consequently the degree of slackrestoring movement of the rack bar incident to the entrainment of the rack bar with the radial teeth of the stopped pawl and to be moved on the slack take-up stroke of the rack bar to an angular position where its weight mass will bias the initial tooth of the pawl adjacent the blank toothless portion to constant'entrainment with the rack bar to permit the rack bar to advance relatively to the pawl on a slack take-up stroke but to prevent loss of ntrainment of the pawl teeth with therack bar, and means for'rotating the pawl to a position where all of the radial teeth including the initial tooth are disengaged from the rack bar to permit the rack bar without interference from the pawl to move to an origin position in the direction of slack-restoring movement. 1 I I Y 5. A slack adjuster for railway car foundation brakes comprising a movable rack barhaving slack take-up and slack-restoring strokes and adapted to be connected to the brake rigging, a rotary pawl having a segment of radial teeth meshingwith the rack bar-teeth for driving the pawl from the rack bar in relatively opposite directions incident to the stroke movements of the rack bar, said rotary pawl having a'blank tooth less segment adjoining the radial teeth and angularly positioned to be brought oppositethe rack barwhen the pawl is rotated in slack take-up direction to permit the rack bar to move rela tively to the pawl in the act of taking up slack in the rigging, a stop weight on the pawlpositioned to encounter'the rack bar as a stop to arrest the rotary movement of the pawl and consequently the degree of slack-restoring movement of the rack bar incident to the entrainment of the rack bar with the radial teeth of the stopped pawl andto be moved on the slack take-up stroke of the rack bar to an angular position where its weight mass will bias the initial tooth of the pawl adjacent the blank portion to constant entrainment with the rack bar to permit the rack bar to advance relatively to thepawl on a slack take-up strokebut to prevent loss of entrainment of the pawl teeth with the rack bar,'and means on the stop .weight positioned to interlock with the rack barin the stopped position of the weight to assist the radial teeth in resisting further slack-restoring movement of the rack bar. v6. A slack adjuster for railway'car foundation brakes comprising a support, a rack bar'movable in the support on'slackjtake-up and slack-restoring strokes adapted to be connected to'the brake rigging; a rotary pawlhaving a segment of radial teeth meshing with the rack bar teeth for driving the pawl from the rack bar in relatively opposite directions incident to the strokemovements of the rack bar, said pawl having a blank toothless segment adjacent the toothed segment positioned to be brought opposite the rack bar when the pawl is rotated in slack take-up direction to permit the rack bar to move relatively to the pawl in the act of taking up slack in the rigging, an eccentric weight mass on the pawl, a stop supported by said support in the path of the eccentric weight mass to arrest the rotary movement of the pawl when the pawl has rotated substantially through its toothed segment in slackrestoring direction whereby to arrest further movement of the pawl and consequently further movement of the rack bar incident to the entrainment of the rack bar with the radial teeth of the stopped pawl, said eccentric weight mass being also so angularly related to the initial tooth of the pawl adjacent the blank portion that it will bias such initial tooth to constant entrainment with the rack bar when the rack bar is moved on the slack take-up stroke.

7. A slack adjuster for railway car foundation brakes comprising a rack bar having slack takeup and slack-restoring strokes and adapted to be connected to the brake rigging, a support for the rack bar, a rotary pawl having a plurality of radial teeth all'struck on a common circle to which the rack bar is tangent and meshing with the rack bar teeth for driving the pawl from the rack bar in relatively'opposite directions in cident to the stroke movements of the rack bar, said pawl also having a blank toothless segment adjacent the plurality of teeth positioned to be brought opposite the rack bar when the pawl is rotated in slack take-updirection to permit the rack bar to move relatively to the pawl in the act of taking up slack in the rigging, a weight mass on the pawl, a stop supported by said-support in the path of the weight mass to arrest the rotary movement of the pawl when the pawl has rotated substantially through its plurality of teeth in slack-restoring direction whereby to arrest further movement of the pawl and consequently further movement of the rack bar incident to the entrainment of the rack bar with at least-one of the teeth of thestopped pawl, said weight mass being so angularly relatedto the initial'tooth of the pawl adjacent the blank portion that it will bias such initial tooth to constant entrainment with the rack bar when the rack bar is moved on the slack take-up stroke.

8. A slack'adjuster for railway car foundation brakes comprising a support, a rack bar movable in the support on slack take-up and slack-restoring strokes adapted to be connected to the brake rigging, a rotary pawl having a segment involving a plurality of radial teeth meshing with the rack bar' teeth for driving the pawl from the rack bar in relatively opposite directions incident to the stroke movements of the rack bar, said pawl havinga blank toothless segment positioned to be brought opposite'the rack bar when the pawl is rotated in slack take-up direction to permit the rack bar'to move relatively to the pawl in the act of taking up slack in the rigging, a stop supported by said support, stop means on the'pawlfor" encountering the support stop to arrest the rotary movement of the pawl when the pawl has rotated substantially through its toothed segment in slack-restoring direction whereby consequently to arrest further movementof the rack bar incident to the entrainment of the rack :bar with at least one tooth of the stopped paw1, and'means on the pawl for biasing the initial tooth adj oiningthe blank portion'to constant entrainmentwith the rack bar when the rack bar is moved on the slack take-up stroke.

9. An improved slack adjuster for railway car foundation brakes as claimed in claim 8 characterized by the fact that said rack bar is also rotatably mounted and is substantially round in cross-section to enable its teeth to be rotated out of alignment with the teeth of the pawl.

10. An improved slack adjuster for railway car foundation brakes as claimed in claim 8 characterized by the fact that the rack bar is substantially round in cross-section and rotatably mounted and its teeth are confined to one sector of the bar whereby rotation of the bar will remove the teeth from engagement with the teeth of said pawl to enable the rack bar to be moved back and forth freely without interference from the stop function of the pawl.

11. A slack adjuster for railway car foundation brakes as claimed in claim 8 in which the said support is pivotally mounted for aligning the rack bar with connectable parts of the brake rigging.

12. A slack adjuster for railway car foundation brakes as claimed in claim 8 in which the said support is a saddle for slidably supporting the rack bar and holding said rack bar in position where its teeth may be engaged by the teeth of said pawl, said saddle being pivotally supported about the center of rotation of said pawl.

13. A slack adjuster for railway car foundation brakes as claimed in claim 8 in which the last named means is an offset portion of the pawl having a heel, and a stop on the support positioned to encounter said heel to prevent overthrow of the pawl past a dead center position.

14. A slack adjuster for railway car foundation brakes as claimed in claim 8 further comprising a pinion journaled in the support in continuous mesh with said rack bar, means for rotating said, pinion in either direction, a trip member rotatably mounted in said support, said trip member and pawl having complementary means for entraining said pawl to move with the trip member, and means for angularly moving said trip member.

15. A slack adjuster for railway car foundation brakes as claimed in claim 8 further comprising means for shifting the rack bar back and forth,

a trip member rotatably mounted on said support,

said trip member and pawl having complementary means for entraining the pawl to move with the trip member, means for angularly moving said trip member, and stop means on the support and trip member to restrict the angular movement of the trip member in both directions.

16. A slack adjuster for railway car foundation brakes as claimed in claim 8 further comprising a trip member movably mounted on the support, said trip member and pawl having complementary end engaging parts positioned to be engaged when the rack bar rotates the pawl on its full slack take-up stroke, and means to move the trip-member to further rotate the pawl in a direction to withdraw all teeth of the pawl from the rack bar to permit the rack bar to be moved back and forth inthe support without interfer ence from said pawl.

17. A slack adjuster for railway car foundation brakes as claimed in claim 8 further comprising means for moving the rack bar back and forth, a trip member rotatably mounted in the support, said pawl and trip member having complementary teeth positioned to be engaged when the. pawl is rotated to a position where its 16 initial tooth only is engaged with the rack bar, andv means to rotate the trip member to cause a further rotation of the pawl to free the initial tooth of the latter entirely from the teeth of the rack bar.

18. A slack adjuster for railway car foundation brakes as claimed in claim 8 further comprising a pinion meshing with the rack bar, means for rotating said pinion to drive the rack bar back and forth, a trip member co-axial with the pinion and independently rotatable, means for rotating said trip member, said trip member and pawl having end engaging teeth adapted to be brought into engagement when the pawl is rotated to a position where the initial tooth only meshes with the rack bar.

19. A slack adjuster for railway car foundation brakes as claimed in claim 8 further comprising a pinion in mesh with the rack bar, a pinion shaft connected to support the pinion and extending to the side portion of the car, a sleeve independently rotatable over said pinion shaft, a trip member fixed to said sleeve, said trip member and pawl having teeth adapted to be brought into engagement when the pawl is rotated to a position in which its initial tooth only meshes with the rack bar, and end handles on said pinion shaft and sleeve accessible at the side portion of the car for independently rotating said pinion shaft and sleeve.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 407,942 Newcomb July 30, 1889 987,272 Valiquet Mar. 21, 1911 1,203,840 Bailey Nov. 7, 1916 1,612,781 Sauvage Dec. 28, 1926 1,623,108 Gormley Apr. 5, 1927 1,680,515 Gormley Aug. 14, 1928 1,681,057 Sauvage Aug. 14, 1928- 1,947,403 Camp Feb. 13, 1934 1,947,405 Camp Feb. 13, 1934 2,181,700 Leichsensing, Jr. Nov. 28, 1939 2,190,681 Robinson Feb. 20, 1940 FOREIGN PATENTS Number Country Date 582,514 Great Britain Nov. 19, 1946 

